(i) Technical Field
The present invention relates to a vertical cavity surface emitting laser, a vertical cavity surface emitting laser device, an optical transmission device, and an information processing apparatus.
(ii) Related Art
A vertical cavity surface emitting laser (VCSEL) is used as a light source in a communication device and an image forming apparatus. In an exemplary selective oxidation type vertical cavity surface emitting laser, a current narrowing layer on which an oxidized aperture is formed by a selective oxidation process is located in a vertical resonator structure. The oxidized aperture has a function to narrow a current injected from an electrode, and inject a high density current to the inside of an active region. In addition, the oxidized aperture has a function to confine a light generated in the active region to a light emitting center with a refractive index difference between the inside and the outside of the oxidized aperture. Furthermore, the oxidized aperture controls a polarization plane of a laser beam to the long axis direction of the oxidized aperture by forming the planar shape of the oxidized aperture to an ellipsoidal shape in a substrate surface which is perpendicular to the optical axis.